The present invention relates to a Point of Sale (POS) system having a plurality of cash registers connected to a single file control unit.
As shown in FIG. 1, in point of sale (POS) systems used for sales data registration in, for example, department stores or supermarkets or the like, electronic cash registers (ECR) 1 are connected to single file control unit 3 via transmission path 2. Center file 4 is provided in a memory section such as a magnetic disk recording device in file control unit 3. Center file 4 stores article data such as article names, unit prices and the like of all articles to be sold and registered by each ECR 1, and sales data such as the number of sold articles, amount of sales and the like for every article code such as a price look-up (PLU) code. Back-up file 5 is used when article data stored in center file 4 cannot, for some reason, be searched, or when the number of sold articles or the amount of sales under each article code, based on the article data, cannot be collected.
When the article code of the article sold to a customer is inputted to each ECR 1 by operating a keyboard's keys or by using a bar code scanner as an input device, this article code is transmitted as article data inquiry information from the ECR to file control unit 3 through transmission path 2. After reception of the inquiry information from each ECR 1, file control unit 3 searches center file 4 on the basis of the article code of the inquiry information. The article data corresponding to the article code is read out and sent to the relevant ECR 1. After reception of the article data, ECR 1 then executes the sales data processing operation using the article name, unit price, etc., of this article data. After completion of the sales data processing operation, sales data such as the amount of sales, number of sold articles, etc., is sent from ECR 1 to file control unit 3, together with the article code. File control unit 3 then accumulatively stores the number of sold articles and the amount of sales into the number-of-articles area and the amount of sales areas which are provided in center file 4 and designated by the relevant article code. In this manner, the sales data registration process for one article is completed.
In such a POS system, since data is transferred between each ECR 1 and one file control unit 3 to execute the sales data registration process, the amount of data transmitted through transmission path 2 increases remarkably, bringing about a concomitant increase in the loads of transmission path 2 and an unshown line control circuit. Thus, if transmission path 2 and the line control circuit fail, sales data registration in each of electronic cash registers 1 cannot be executed.
As a general means of avoiding such a problem, the arrangement shown in FIG. 2, where each electronic cash register 7, connected to file control unit 6 through transmission path 2, is equipped with its own terminal file 8, can be employed. The article data of all articles is filed for every article code in terminal file 8. When an article code is inputted via the keyboard or bar code scanner of one ECR 7, corresponding article data such as article name, unit price, etc., is read out by searching terminal file 8 of the given ECR according to the article code, thereby executing the sales data processing operation. This ECR 7 then sends the sales data of the number of sold articles, amount of sales and the like to file control unit 6 through transmission path 2 in a manner similar to the above. File control unit 6 then updates the number of sold articles and the amount of sales of the relevant article of center file 9, based on the received sales data.
Using the POS system described above there is no need for each ECR 7 to transfer article data inquiry information to file control unit 6, or for file control unit 6 to transmit the article data to each ECR 7. As a result, the amount of data transmitted by transmission path 2 is markedly reduced.
However, the following problems still remain, even the POS system in which each ECR 7 has been equipped with its own terminal file 8. Namely, in so far as it is necessary to store the article data of all articles to be sold at the shop into each ECR 7's terminal file 8, each terminal file 8 needs a memory capacity which is substantially the same as that of center file 9, provided for file control unit 6. The problems of a need to increase the size of each ECR 7, and an accompanying increase in manufacturing costs, become paramount.
In addition, since the unit prices of articles are frequently changed in supermarkets or the like, it is necessary to change the unit prices stored in each ECR 7's terminal file 8 every time the unit prices are changed. As this procedure is fairly complicated, it not only increases the workload of the operator but also induces a deterioration in the working efficiency of the whole sales data processing operation. This latter problem is particularly worrisome with respect to the probability of misoperation, which increases each time unit prices have to be changed.